Proof of Theorem: Composite Function Inverse

[irvin.b]

i really need to see the proof of this theorem:

if f and g are bijective then the inverse of (g o f) = inverse of f o inverse of g

 

[irvin.b]

i hope you will help me..

 

[statdad]

what have you tried?

 

[Tac-Tics]

Hint: define f(x) = y and g(y) = z.

 

[Landau]

Just compute (g o f) o (g o f)^-1 and (g o f)^-1 o (g o f) and see that they both give you the identity.